Tenter frame

ABSTRACT

The specification discloses a tenter frame of the type which laterally stretches webs of material. The new construction provides for two separate parallel rails, one rail providing a pull track, and the other rail providing a return track wherein the tenter chain is located outside of the oven. In this manner, the tenter chain is exposed to ambient temperatures and cooling during the non-working return cycle. New structures are provided at the entering end and delivery end of the tenter frame to accommodate the dual rail structures.

451 Apr. 17', 1973 The new construction provides for two separate parallel rails, one rail providing a pull track, and the other rail y end of ail struc- .1. Jlnlv 0 3 5 i 2 ETA l 9 m M M 3 m; 5

/ a I M 6 w an H 3,327,367 6/1967 Dungler.... 3,529,332 9/1970 Primary Examiner-Robert R. Mackey Attorney-William Frederick Werner [57] ABSTRACT The specification discloses a tenter frame of the t which laterally stretches webs of material.

providing a return track wherein the tenter chain is located outside of the oven. In this manner, the tenter chain is exposed to ambient temperatures and coolin during the non-working return cycle. New structur are provided at the entering end and deliver the tenter frame to accommodate the dual r tures.

5 Claims, 18 Drawing Figures a \w m z 6 r o M E n MEDEEEFHWI- m .26/57 R UX TENTER FRAME Inventors: Frederick Hyatt, Providence; Frederick Earl Arruda, Coventry, both of R1.

Assignee: Bevis Industries, Inc., Providence,

[22] Filed: Aug. 17, 1970 {21] Appl. No.: 64,303

[52] US. R, 26/61 B [51] Int. ......D06c 3/02 [58] Field of Search....................26/57 R, 61 A, 61 B [56] References Cited UNITED STATES PATENTS 2,l47,l l5 2/1939 Williams, Jr. 3,303,528 2/1967 Gageur et 25 United- States Patent 1 Hyatt et al.

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INVENTORS FREDERICK HYATT FREDERICK EARL ARRUDA yI-WJJ'M AT TORNEY PATENTEI] APRI 7 I973 SHEET 3 (IF 8 A z 0%.? m o m 1 H H PM m f wm AH.

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sumunrs FREDERICK HYATT FREDERICK EARL ARRUDA BY sawdira ATTORNEY PATENTEB APR 1 7197s 7 27g swan 5 0F 8 INVENTORS FREDERICK HYATT FREDERICK EARL ARRUDA BY ji ut n1 ATTORNEY PATENTEDAPR 1 71973 2 3 sum 15 0F 8 A44 /77 [Z5655 /Z4 INVENTORS FREDERICK HYATT FREDERICK EARL ARRUDA BY 2033(4): QMmd ATTORNEY PATENTED PR 1 H975 SHEET 7 BF 8 S m T N E V W FREDERICK HYATT FREDERICK EARL ARRUDA M aw! 30M ATTORNEY TENTER FRAME This invention relates to apparatus for stretching ,webs of material and more particularly it relates to a tenter frame for laterally stretching material to increase the width thereof.

An object of the present invention is to provide apparatus for stretching webs laterally within a smooth, reverse curve track while gripping the web along opposite edges by means of tenter clips.

Another object of the present invention is to provide adjustable apparatus in the nature of a tenter frame for varying the path of travel of two oppositely located tenter clip chains, each tenter clip chain being guided in a closed path by two separate tenter frame rail tracks.

Still another object of the present invention is to divide the single rail section having a pull side track and a return side track into two separate sections having, respectively, a pull side track and a return side track, so that the return side track exposes the tenter clip chain to ambient temperature and a cooling medium, while the pull side track is located within the drying oven housing.

Another object of the present invention is to separate the pull side track from the return side track so that the return side track and the tenter clip chain may be disassembled for repairs and maintenance. In prior constructions a rail section consisted of a pull side track and a return side track with a pivotal connection between adjacent rail sections to permit relative movement between adjacent rail sections and termally induced expansion and contraction between adjacent rail sections.

With the advent of synthetic fibers and the processing of plastic film on a tenter frame, drying temperatures increased and the need for greater relative movement between adjacent rail sections increased. If the tenter frame was to continue its function, it had to enable the tenter clip chain to be cooled when not in the extremely hot drying oven, and to form an arcuate curve by means of straight rail sections, in very short linear distances.

The separation of each rail section into two separate but parallel rail sections offered a solution to the problem but created other problems at the sprocket heads located, respectively, at the entering end and discharge end of the tenter frame.

Each separate but parallel rail section at the entering end and discharge end of the tenter frame was provided with a separate pivot pin in the respective saddle. Movement of the sprocket heads toward and away from each other at the respective ends of the tenter frame, caused the relative distance between the respective pivot pins of the rail sections and sprocket to vary greatly.

It is therefore, an object of the present invention to provide a structure which solves these problems.

Other objects of the present invention will be pointed out in part and become apparent in part in the following specification and claims.

In the specification and claims the term web includes any type of web material such as cotton, wool, synthetic fiber, plastic film, aluminum foil, glossy paper, non-woven material, etc.

Referring to the drawings in which similar characters of reference indicate corresponding parts in all the figures:

FIG. 1 is a plan view of the new and improved tenter frame with a schematic showing; of the two tenter. clip chains.

FIG. 2 is a fragmentary vertical cross sectional view taken on line 2--2 of FIG. 1, with the adjacent section omitted.

FIG. 3 is a view taken on line 3-3 of FIG. 1.

FIG. 4 is an enlarged plan view of one sprocket idler and set of rail sections at the entering end of the tenter frame.

FIG. 5 is a side elevational view of FIG. 4.

FIG. 6 is a rear elevational view of FIG. 4.

FIG. 7 is a vertical sectional view taken on line 77 of FIG. 4.

FIG. 8 is a vericalsectional view taken on line 8-8 of FIG. 4.

FIG. 9 is an enlarged plan view of a drive sprocket wheel and a set of rail sections at the discharge end of the tenter frame.

FIG. 10 is a side elevational view of FIG. 9, partly in section, as seen from line 10, 10 in FIG. 1.

FIG. 1 1 is a vertical sectional view taken on line 1 1- ll of FIG. 9.

FIG. 12 is a vertical sectional view taken on line 12- 12 of FIG. 9.

FIG. 13 is a vertical sectional view taken on line 13-- 13 of FIG. 4.

FIG. 14 is an exploded perspective view of the saddle.

FIG. 15 is a perspective view of one pair of parallel rail sections.

FIG. 16 is a fragmentary perspective view of adjacent rail sections, partly in section, pivotally connected together by means of a pivot pin slidably mounted in a saddle.

FIG. 17 is a view, similar to FIG. 2, showing a modified form of saddle construction.

FIG. 18 is a view, similar to FIG. 3, showing the modified form of saddle construction depicted in FIG. 17.

In proceeding with this invention, reference is made to the drawings, wherein is illustrated the new and improved tenter frame, which consists of stands 10, cross members 11, saddles 12, and rail sections 65, 165.

The stands 10 are fastened, as by welding, to opposite ends of the cross members 11. Side members (not shown) may be fastened to the several cross members or the tenter frame may consist of a plurality of cross members 11 as shown in FIG. 1.

The cross members 11 (see FIGS. 5 and 13) are preferably in the form of I beams with the tops 14, right sides 15 and left sides l6 machine finished to form a track (see FIGS. 2,3, and 13 Three bearings 17, 18 and 19 (see FIGS. 1, 2, and 3) are adapted to engage tops 14 and grip, respectively, right sides 15 and left sides 16. Bolts 20 fasten, respectively, bearings 17, 18, 19 to cross members 11.

Shafts 22 provided with right hand threads 23 and left hand threads 24 are rotatably mounted in bearings 17, 18, and 19. Hand wheels 25 may be fastened so as to rotate shafts 22.

Saddles 12 (see FIG. 14) areprovided with sliding faces 26, 27 and sliding ends 28, 29 which engage, respectively, tops 14, left sides 16 and right sides 15 (see FIGS. 2 and 3).

Saddles 12, (see FIGS. 2 and 14) are provided with chambers 30, 31, and 32, formed, respectively by walls 33, 34, 35 and 36. Each of said walls are provided with clearance areas 37 so that the threaded areas of shafts 22 may freely rotate therein.

Each saddle 12 (see FIGS. 2, 3, and 14) is provided with two blocks 40 and 41. Block 40 is provided with a pull side groove consisting of bottom 42 and sides 43, 44. Two gibs 45, 46 are fastened, respectively, to the tops 43A, 44A of sides 43, 44 as by means of screws 45A passing thru orifices 47 and fastening in screw threads 48.

Block 41 is provided with a return side groove, generally indicated by reference numeral 49, and provided with a top surface 49A.

A pivot pin, generally indicated by reference numeral 50, consists of an enlarged head 51 having a shoulder 52 and a shank 53. Enlarged head 51 slides upon bottom 42 and slidably engages sides 43, 44 while shank 53 projects upwardly between the edges of gibs 45, 46. Gibs 45, 46 engaging shoulder 52 prevents pivot pin 50 from moving upwardly out of the track.

A pivot pin 50A consists of an enlarged head 51A having a shoulder 52A and a shank 53A. Enlarged head 51A slides in groove 49 while shank 53A projects upwardly above top surface 49A.

A nut 54 provided with a screw thread 55 of a hand adapted to rotatably engage left hand threads 24 is located in chamber 32 and is held therein by means of walls 35 and 36. Wall 36 is fastened to saddle 12 by means of screws 75 fastened in screw threads 368 located in saddle l2.

Rotation of hand wheel 25 causes nut 54 to engage wall 35 or 36 to slide saddle 12 upon cross member 11 toward or away from bearing 19.

The plurality of rail sections are indicated in FIG. 1 as 65, 65A, 65B, 65C, 65D, and 65E constituting a pull side track. The plurality of rail sections indicated as 165, 165A, 165B, 165C, 165D and 165E constitute a return side track.

Each rail section is identical to the other rail sections in structure. Reference is made to FIG. wherein rail section 65 is provided with a base 66 having a cut away area on one end to provide a hinge plate 67 and a cut away area on the opposite end to provide a bottom platform 68. Hinge plate 67 and bottom platform 68 are provided, respectively, with pin bores 69, 69A. A body portion projects upwardly from base 66 to provide a tenter clip track consisting of a bottom slide surface 70, a front face 71, and an arm 72 having a top case surface 73. Arms 72 may be relieved of weight, as with an opening 74.

Pin bore 69A is placed upon shank 53A in FIG. 16, with bottom platform 68 resting upon shoulder 52A. Hinge plate 67 lays upon bottom platform 68 and is pivotally connected to shank 53A. Head 51A is slidably mounted in groove 49. In this manner, a sliding and pivoting connection is provided between the ends of rail sections under control of shaft 22. This description is to the rail sections constituting the return side track.

traverse of shank 53. Bottom platform 68 lays upon the top surface of gibs 45, 46 with pin bore 69A mounted upon shank 53.

Hinge plate 67 lays upon bottom platform 68 and is pivotally connected to shank 53. In this manner, a sliding and pivoting connection is provided between the ends of rail sections under control of shaft 22 on the tenter clip chain pull side track. Gibs 45, 46 prevent head 51 from lifting away from bottom 42 when the rail sections are under the influence of the force exerted by the tenter clips forming the tenter chain.

The structure at the entering end of the tenter frame will now be described. Reference is made to FIGS. 1, 4, 5, 6, 7, 8 and 13.

Two cross members 11A and 11B are supported upon an end stand 10A. A saddle block 41A provided with an open ended chamber 32A, a wall 35A and a return side groove 49, is slidably mounted upon cross Reference is now made to the pull side track,

member 1113 by means of sliding ends 28A, 29A which engage respectively, left side 16A and right side 15A on cross member 11B and top 14A.

A nut 54A located in chamber 32A engages the threads 24A on shaft 22A. A wall 36A fastened to saddle block 41A by means of screws 75 is provided with a clearance orifice to permit threads 24A to pass therethrough.

A pivot pin 76 having an enlarged head 77 is slidably mounted in the return side groove 49 by means of head 77. Bottom platform 68 of rail section 165 slidably engages the top surface 49A of saddle block 41A and is pivotally connected to the pivot pin 76 through pin bore 69A.

Similarly, a saddle block 40A provided with a chamber 30A and walls 33A and 34A each having clearance areas 37A is slidably mounted upon cross member 118 by means of sliding ends 28A, 29A which engage respectively, left side 16A and right side 15A and top 14A on cross member 1 1B.

Saddle 40A is provided with a groove consisting of a bottom 42B, and sides 43B and 448. Two gibs 45B and 46B are fastened to saddle block 40A. A pivot pin 81 provided with an enlarged head 82 having a shoulder 83 is slidably mounted in said groove with said enlarged head 82 slidably engaging bottom 42B, sides 43B and 448 with pivot pin 81 projecting upwardly between gibs 45B and 46B of rail section 65.

An entering saddle is slidably mounted to the top 14C and sides 16C, 15C of cross member 11A through sliding face 94 and sliding ends 95, 96, respectively. Gibs 97, 98 are fastened to saddle 90 to prevent saddle 90 from lifting off cross member 1 1A.

Saddle 90 is provided with a groove 100. Gibs 101, 102 are fastened to saddle 90. A pivot pin 103 having an enlarged head 104 is slidably mounted in groove with pivot pin 103 projecting upwardly past gibs 101, 102.

A yoke having a base 105, and a spider provided with a seat 106 is pivotally connected to pivot pin 103 through an orifice provided for that purpose. A spring washer 108 prevents base from lifting off pivot pin 103.

An entering rail 111 axially provided with an inner hub 112 and outer hub 113 is externally provided with a bottom platform 114 having a pin bore 116 and a hinge plate 115 having a pin bore 117. (see FIGS. 4, 7 and 8) Bottom platform 114 through pin bore 116 is pivotally mounted to pivot pin 81 and slidably mounted upon gibs45B, 46B. Hinge plate 115 thru pin bore 117 is pivotally mounted to pivot pin 76 and slidably mounted upon bottom platform 68.

Outer hub 113 is fastened to spider seat 106 by means of screws 118. Inner hub 112 is provided with an axial bore 120which forms a shoulder 121. A carriage 123 supported upon shoulder 121 is located within axial bore 120. A carriage cap 124 is fastened to carriage 123 by means of screws 125 and underlies inner hub 112 to prevent carriage 123 from being lifted out of axial bore 120. A carriage stud 127 is fastened to carriage 123 by means of screw threads 128. A sprocket hub 130 is mounted for free rotation upon carriage stud 127. A sprocket 131 is fastened to sprocket hub 130 by means of bolts 132. A tenter clip jaw opening wheel 133 is fastened to sprocket hub 130 by means of capscrews 135. A washer 136 overlies wheel 133 and is fastened to carriage stud 127 by means of bolt 139.

v The structure at the delivery end of the tenter frame will now be described with reference to FIGS. 1, 9, 10, 11 and 12.

Two cross members 141, 142 are fastened to and supported on one end by a stand 143 and on the other end by a stand 144. A stand 149 supporting cross members 141, 142 is located midway between stands 143, 144. These stands are fastened to a floor.

A mounting plate 145 provided with an axial opening 146 is slidably mounted upon cross members 141, 142. A front gib 147 and a rear gib 148 are fastened to opposite ends of mounting plate 145 to guide plate 145 in sliding transverse movement back and forth upon cross members 141 and 142.

A gear box 150 is provided with a flange 151 and a vertical drive shaft 152. Screws 153 fasten flange 151 to mounting plate 145. A delivery rail end 154 is supported upon a shoulder 155 provided upon mounting plate 145 for free swivel movement. A cap 156 is fastened to gear box 150 with drive shaft 152 projecting through an opening in the cap 156. A sprocket hub 157 is is fastened to drive shaft 152 for rotational movement. A sprocket 160 is fastened to sprocket hub 157 by means of bolts 161. A tenter clip jaw opening wheel 162 is fastened to sprocket hub 157 to rotate therewith. A washer 163 overlies drive shaft 152 and is fastened thereto by means ofa bolt 164.

A pivot pin 175 is fastened to a collar so as to provide an enlarged head 176 which is slidably mounted in a groove 178 located in mounting platel45. Pivot pin 175 pivotally connects delivery end rail 154 with track rail section 165E. A second pivot pin 177 is fastened to a collar so as to provide an enlarged head 178 which is slidably mounted in a groove 179 located in mounting plate 145. Pivot pin 177 pivotally connects delivery end rail 154 with track rail section 65E.

In like manner, a second mounting plate 145A is slidably mounted upon cross members 141, 142. A second gearbox 150A provided with a vertical drive shaft is fastened to mounting plate 145A. Delivery rail end 154A is supported upon mounting plate 145A for free swivel movement. A second sprocket hub 157A is fastened to a drive shaft located under washer 163A in FIG. 1 and corresponding to drive shaft 152 in FIG. 12, for rotational movement. A sprocket 160A is fastened to sprocket hub 157A. A tenter clip jaw opening wheel 162A is fastened to sprocket hub 157A to rotate therewith. A washer 163A overlies drive shaft 152A and is fastened thereto by means of bolt 164A.

A pivot pin 175A is slidably mounted in mounting plate A. Pivot pin 175A pivotally connects delivery end rail 154A with track rail section 165E. A second pivot pin 177A is slidably mounted in mounting plate 145A. Pivot pin 177A pivotally connects delivery end rail 154A with track rail section 65B.

A splined shaft 190 rotatably supported on opposite ends in gear boxes 150, A connects the gears (not shown) in gear boxes 150, 150A as a common drive connection. A motor (not shown) connected to the end of splined shaft 190 drives shafts 152, 152A in unison and thereby rotates sprockets 160, A and tenter clip jaw opening wheels 162, 162A.

Reference is now made to FIG. 1. Shaft 22A is pro vided in two sections for independent rotation. One section 22B is provided with screw 23A. The other section 22A is provided with screw 24A. The ends of shafts 22A, 22B are rotatably mounted in bearing 18A.

This structure permits tenter clip jaw opening wheel 133 to be independently adjusted in relation to tenter clip jaw openning wheel 133A for the accurate adjustment of rail sections 65, 65' to each other to accommodate the width of the material to be gripped upon opposite sides by the tenter clips T1 and T2 forming tenter chains 1 and 2.

The appropriate hand wheels are then individually rotated so that shafts 22A and 22B through threads 24A, 23A position saddle blocks 40A, 41A as a unit and 40C, 41C as a unit relative to each other as units. In this manner, rail sections 65, as a unit and 65 and 165' as a unit are positioned relative to each other. Each unit constituting two oppositely disposed relatively adjustable ends of two endless tenter clip tracks for tenter clip chains 1 and 2.

Hand wheel 25F is then rotated to position tenter clip jaw opening wheels 162, 162A relative to each other a distance equal to the width of the material at the delivery end of the tenter clip chains 1 and 2.

Hand wheels 25 are then rotated to position saddles 12, 12' and rail sections relative to each other and to the respective ends of the tenter frame to form two oppositely disposed contour paths by means of the pivotally connected rail sections.

Cross members 141, 142 (as previously stated) are fastened to stands fixed to a floor. The movement of shafts 152, 152A and delivery rail ends 154, 154A toward and away from each other causes the rail sections which are slidably mounted in the saddles 12', 12 to slide toward and away from the entering end of the tenter frame and entering rails l 1 1A and 1 1 1B.

The center distances between pivot pins 175, .177

and shaft 152 remain constant because shaft 152 moves and rail sections 165, 165A, etc., constituting a return i side track, to slide in varying distances relative to each other in their respective saddles 12. Therefore, entering rail 111 will rotate as rail section 65 acting thru pivot pin 81 moves entering rail 111 around pivot pin 103 while simultaneously, rail section 165 acting thru pivot pin 76 moves entering rail 111 around pivot pin 103. Entering rail 111 must therefore not only rotate but it must slide along cross member 11A to adjust itself into a position of equilibrium under the influence of the forces imposed by the movement of rail sections 65, 165 relative to each other. In this manner, the linear distance of the tenter clip chain track from shaft 152 to shaft 127 remains constant, as it must in order to accommodate a tenter clip chain having a fixed length. If entering rail 111 did not slide laterally upon cross member 11A it would bind and cause the rail sections to rupture at a saddle.

Reference is now made to FIGS. 17 and 18 wherein is depicted modified form of the saddle shown in FIGS. 2, 3 and 14. The two differences in structure are l the saddle 12 of FIGS. 17 and 18 is made in two parts, instead of one part, so that blocks 40 and 41 become independent of each other and (2) block 40 is provided with a nut 54A so that blocks 40 and 41 are individually moved through the rotation of the screw on shaft 22. In this manner block 40 may be spaced on shaft 22 an independent relative distance from block 41 instead of a fixed distance as disclosed in FIGS. 2 and 3. One block 40 or 41 can therefore be placed on either side of an oven wall (not shown) which may be placed between blocks 40, 41. Therefore, a tenter clip chain guided in the return track slidably mounted in block 41 can be placed outside the oven for cooling.

It will be noted with reference to FIGS. 2 and 17 that a vertical plane X-X which passes through the front face 71 also passes through the vertical center of the respective pivot pin 53 of the rail section. In this manner, the gap between the adjacent rail section front faces 71 is reduced to an absolute minimum regardless of the direction of divergence of adjacent rail section front faces 71.

This minimum gap reduces the jar usually associated with the rail engaging face ofa tenter clip traversing the gap between rail section front faces. Thus, the tenter clip chain vibration is reduced to an absolute minimum.

Having shown and described preferred embodiments of the present invention, by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of the present invention.

What we claim is:

1. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, a plurality of saddles, two for each cross member, each saddle having two block members, each block member having a groove, a plurality of pivot pins, one for each groove, each pivot pin having an enlarged head slidably mounted in a groove, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, means rotatably mounting a shaft to a cross member, means slidably mounting two saddles to each cross member, means connecting one saddle to a right hand thread and a second means connecting the second saddle to the left hand thread, whereby rotation of the shaft moves the two saddles on a cross member toward and away from each other. a plurality of rail sections, each rail section having a pin bore at opposite ends, opposite ends of adjacent rail sections being pivotally connected to pivot pins through said pin bores with the rail sections pivotally and slidably supported upon block members, each rail section having a track provided with a front rail face, there being a sufficient number of cross members, saddles and rail sections to form two oppositely disposed endless front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return side front rail face track, said pull side and said return side being separated by the distance between said two block members on each saddle, a first cross member and a second cross member provided at one end of said frame in spaced parallel relation to said plurality of cross members, two entering saddles, means independently and slidably mounting each of said two entering saddles to said first cross member, two yokes, one for each entering saddle, pivot means pivotally and slidably connecting a yoke to an entering saddle, two entering rails, one for each yoke, means fastening an entering rail to a yoke, two carriages, one for each entering rail, means pivotally connecting a carriage to an entering rail, two sprocket hubs, two sprockets and two tenter clip jaw opening wheels, a hub, a sprocket and a wheel for each carriage, carriage stud means pivotally connecting a sprocket hub to a carriage, means fastening a sprocket to a sprocket hub, means fastening a tenter clip jaw opening wheel to a sprocket hub, a first shaft having a left hand thread, a second shaft having a right hand thread, bearing means rotatably mounting said first shaft and said second shaft to said second cross member for independent relative rotation to each other, four saddle blocks formed into two pairs of blocks, means slidably mounting said four saddle blocks to said second cross member, means connecting one of each of said pair of blocks, respectively, to the left hand thread and to the right hand thread, four pivot pins, one for each block, means slidably mounting each pivot pin, in a respective block, each of said two entering rails having a first pin bore and a second pin bore, one of said four pivot pins pivotally connecting a first pin bore to a pin bore in a rail section, a second of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section and a fourth of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, to align said two sprockets, respectively, with said two oppositely disposed endless front rail face track contour paths.

2. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, two saddles slidably mounted to each of said cross members and each having two block members, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, means rotatably mounting a shaft to each cross member, means connecting one saddle of each cross member to a right hand thread and connecting a second saddle of the corresponding cross member to the left hand thread, whereby rotation of the shaft moves the two saddles on the cross member toward and away from each other, a plurality of pivot pins, one for each block member, means slidably mounting each pivot pin in a block member, a plurality of rail sections, each having a track provided with a front rail face and each having a pin bore at opposite ends so as to be pivotally connected to the ends of adjacent rail sections by means of a pivot pin, whereby the rail sections are pivotally and slidably supported upon the block members to form two oppositely disposed front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return side front rail face track, said pull side and said return side being separated by the distance between said two block members of each saddle, two entering rails, one for each of said two oppositely disposed front rail face track contour paths for said two endless tenter clip chains, each entering rail having two oppositely located pivot pin bores, and two entering saddle means slidingly and pivotally mounting one of said two entering rails to a cross member, pivot pins in adjacent block members connecting each of said two oppositely located pivot pin bores of each entering rail to a pin bore of a pull side front rail face track rail section and a return side front rail face track rail section to complete the front rail face track contour paths at one end of said frame, said two entering saddle means including means independently and longitudinally slidably mounting each of said two entering saddles to a cross member, two yokes, one for each entering saddle, pivot means pivotally and laterally slidably connecting a yoke to an entering saddle, two sprockets, one for each entering saddle, and means rotatably mounting a sprocket to a respective entering rail, whereby binding and rupturing of the entering rails at the saddle means is prevented.

3. Apparatus for stretching webs laterally as defined in claim 2, including two mounting plates slidably connected to cross members, two delivery rail ends, one for each mounting plate, means for pivotally connect ing a delivery end to a respective mounting plate, four pivot pins, means slidably connecting two pivot pins to each of said two mounting plates, to pivotally connect a delivery rail end with adjacent track rail sections, said two delivery rail ends completing the front rail face track and the return side front rail face track of said contour paths atthe other end of said frame.

4. Apparatus for stretching webs laterally as defined in claim 2, including two mounting plates slidably connected to cross members, two delivery rail ends, one for each mounting plate, two gear boxes, each having a vertical drive shaft, means fastening a mounting plate to a gear box, a'delivery rail end attached to each mounting plate for free swivel movement, two sprockets, one for each vertical shaft, means fastening a sprocket to a vertical shaft, four pivot pins, means slidably connecting two pivot pins to each of said two mounting plates, to pivotally connect a delivery rail end with adjacent track rail sections, said two delivery rail ends completing the front rail face track and the return side, front rail face track of said contour paths at the other end of said frame.

5. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, a plurality of saddles for each cross member, each saddle having at least one block member, each block member having a groove, a plurality of pivot pins, one for each groove, each pivot pin having an enlarged head slidably mounted in a groove, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, bearing means rotatably mounting a shaft to a cross member, means slidably mounting each of said saddles to a cross member for independent sliding movement, nut means, one for each of said saddles, connecting one group of said saddles to a right hand thread and another group of said saddles to a left hand thread, whereby rotation of the shafts moves the saddles connected to the left hand threads toward and away from the saddles connected to the right hand threads upon the cross members, a plurality of rail sections, each rail section having a pin bore at opposite ends, opposite ends of adjacent rail sections being pivotally connected to pivot pins through said pin bores with the rail sections pivotally and slidably supported upon block members, each rail section having a track provided with a front rail face, there being a sufficient number of cross members, saddles and rail sections to form two oppositely disposed endless front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return front rail face track, a first cross member and a second cross member provided at one end of said frame in spaced parallel relation to said plurality of cross members, two entering saddles, means independently and slidably mounting each of said two entering saddles to said first cross member, two yokes, one for each entering saddle, pivot means pivotally and slidably connecting a yoke to an entering saddle, two entering rails, one for each yoke, means fastening an entering rail to a yoke, two carriages, one for each entering rail, means pivotally connecting a carriage to an entering rail, two sprocket hubs, two sprockets and two tenter clip jaw opening wheels, a hub, a sprocket and a wheel for each carriage, carriage stud means pivotally connecting a sprocket hub to a carriage, means fastening a sprocket to a sprocket hub, means fastening a tenter clip jaw opening wheel to a sprocket hub, a first shaft having a lefthand thread, a second shaft having a right hand thread, bearing means rotatably mounting said first shaft and said second shaft to said second cross member for independent relative rotation to each other, four saddle blocks formed into two pairs of blocks, means slidably mounting said four saddle blocks to said second cross member, means connecting one of each of said pair of blocks, respectively, to the left hand thread and to the right hand thread, four pivot pins, one for each block, means slidably mounting each pivot pin in a respective block, each of said two entering rails having a first pin bore and a second pin bore, one of said four pivot pins pivotally connecting a first pin bore to a pin bore in a rail sections, a second of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section and a fourth of said four pivot pins pivotally connecting a second pin bore 

1. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, a plurality of saddles, two for each cross member, each saddle having two block members, each block member having a groove, a plurality of pivot pins, one for each groove, each pivot pin having an enlarged head slidably mounted in a groove, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, means rotatably mounting a shaft to a cross member, means slidably mounting two saddles to each cross member, means connecting one saddle to a right hand thread and a second means connecting the second saddle to the left hand thread, whereby rotation of the Shaft moves the two saddles on a cross member toward and away from each other, a plurality of rail sections, each rail section having a pin bore at opposite ends, opposite ends of adjacent rail sections being pivotally connected to pivot pins through said pin bores with the rail sections pivotally and slidably supported upon block members, each rail section having a track provided with a front rail face, there being a sufficient number of cross members, saddles and rail sections to form two oppositely disposed endless front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return side front rail face track, said pull side and said return side being separated by the distance between said two block members on each saddle, a first cross member and a second cross member provided at one end of said frame in spaced parallel relation to said plurality of cross members, two entering saddles, means independently and slidably mounting each of said two entering saddles to said first cross member, two yokes, one for each entering saddle, pivot means pivotally and slidably connecting a yoke to an entering saddle, two entering rails, one for each yoke, means fastening an entering rail to a yoke, two carriages, one for each entering rail, means pivotally connecting a carriage to an entering rail, two sprocket hubs, two sprockets and two tenter clip jaw opening wheels, a hub, a sprocket and a wheel for each carriage, carriage stud means pivotally connecting a sprocket hub to a carriage, means fastening a sprocket to a sprocket hub, means fastening a tenter clip jaw opening wheel to a sprocket hub, a first shaft having a left hand thread, a second shaft having a right hand thread, bearing means rotatably mounting said first shaft and said second shaft to said second cross member for independent relative rotation to each other, four saddle blocks formed into two pairs of blocks, means slidably mounting said four saddle blocks to said second cross member, means connecting one of each of said pair of blocks, respectively, to the left hand thread and to the right hand thread, four pivot pins, one for each block, means slidably mounting each pivot pin, in a respective block, each of said two entering rails having a first pin bore and a second pin bore, one of said four pivot pins pivotally connecting a first pin bore to a pin bore in a rail section, a second of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section and a fourth of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, to align said two sprockets, respectively, with said two oppositely disposed endless front rail face track contour paths.
 2. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, two saddles slidably mounted to each of said cross members and each having two block members, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, means rotatably mounting a shaft to each cross member, means connecting one saddle of each cross member to a right hand thread and connecting a second saddle of the corresponding cross member to the left hand thread, whereby rotation of the shaft moves the two saddles on the cross member toward and away from each other, a plurality of pivot pins, one for each block member, means slidably mounting each pivot pin in a block member, a plurality of rail sections, each having a track provided with a front rail face and each having a pin bore at opposite ends so as to be pivotally connected to the ends of adjacent rail sections by means of a pivot pin, whereby the rail sections are pivotally and slidably supported upon the block Members to form two oppositely disposed front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return side front rail face track, said pull side and said return side being separated by the distance between said two block members of each saddle, two entering rails, one for each of said two oppositely disposed front rail face track contour paths for said two endless tenter clip chains, each entering rail having two oppositely located pivot pin bores, and two entering saddle means slidingly and pivotally mounting one of said two entering rails to a cross member, pivot pins in adjacent block members connecting each of said two oppositely located pivot pin bores of each entering rail to a pin bore of a pull side front rail face track rail section and a return side front rail face track rail section to complete the front rail face track contour paths at one end of said frame, said two entering saddle means including means independently and longitudinally slidably mounting each of said two entering saddles to a cross member, two yokes, one for each entering saddle, pivot means pivotally and laterally slidably connecting a yoke to an entering saddle, two sprockets, one for each entering saddle, and means rotatably mounting a sprocket to a respective entering rail, whereby binding and rupturing of the entering rails at the saddle means is prevented.
 3. Apparatus for stretching webs laterally as defined in claim 2, including two mounting plates slidably connected to cross members, two delivery rail ends, one for each mounting plate, means for pivotally connecting a delivery end to a respective mounting plate, four pivot pins, means slidably connecting two pivot pins to each of said two mounting plates, to pivotally connect a delivery rail end with adjacent track rail sections, said two delivery rail ends completing the front rail face track and the return side front rail face track of said contour paths at the other end of said frame.
 4. Apparatus for stretching webs laterally as defined in claim 2, including two mounting plates slidably connected to cross members, two delivery rail ends, one for each mounting plate, two gear boxes, each having a vertical drive shaft, means fastening a mounting plate to a gear box, a delivery rail end attached to each mounting plate for free swivel movement, two sprockets, one for each vertical shaft, means fastening a sprocket to a vertical shaft, four pivot pins, means slidably connecting two pivot pins to each of said two mounting plates, to pivotally connect a delivery rail end with adjacent track rail sections, said two delivery rail ends completing the front rail face track and the return side front rail face track of said contour paths at the other end of said frame.
 5. Apparatus for stretching webs laterally comprising a frame having a plurality of cross members aligned laterally in spaced relation, a plurality of saddles for each cross member, each saddle having at least one block member, each block member having a groove, a plurality of pivot pins, one for each groove, each pivot pin having an enlarged head slidably mounted in a groove, a plurality of shafts, one for each cross member, each shaft having a right hand thread and a left hand thread, bearing means rotatably mounting a shaft to a cross member, means slidably mounting each of said saddles to a cross member for independent sliding movement, nut means, one for each of said saddles, connecting one group of said saddles to a right hand thread and another group of said saddles to a left hand thread, whereby rotation of the shafts moves the saddles connected to the left hand threads toward and away from the saddles connected to the right hand threads upon the cross members, a plurality of rail sections, each rail section having a pin bore at opposite ends, opposite ends of adjacent rail sections being pivotally connected to pivot pins through said pin bores with the raIl sections pivotally and slidably supported upon block members, each rail section having a track provided with a front rail face, there being a sufficient number of cross members, saddles and rail sections to form two oppositely disposed endless front rail face track contour paths of predetermined length for two endless tenter clip chains, each path constituting a pull side front rail face track and a return front rail face track, a first cross member and a second cross member provided at one end of said frame in spaced parallel relation to said plurality of cross members, two entering saddles, means independently and slidably mounting each of said two entering saddles to said first cross member, two yokes, one for each entering saddle, pivot means pivotally and slidably connecting a yoke to an entering saddle, two entering rails, one for each yoke, means fastening an entering rail to a yoke, two carriages, one for each entering rail, means pivotally connecting a carriage to an entering rail, two sprocket hubs, two sprockets and two tenter clip jaw opening wheels, a hub, a sprocket and a wheel for each carriage, carriage stud means pivotally connecting a sprocket hub to a carriage, means fastening a sprocket to a sprocket hub, means fastening a tenter clip jaw opening wheel to a sprocket hub, a first shaft having a left hand thread, a second shaft having a right hand thread, bearing means rotatably mounting said first shaft and said second shaft to said second cross member for independent relative rotation to each other, four saddle blocks formed into two pairs of blocks, means slidably mounting said four saddle blocks to said second cross member, means connecting one of each of said pair of blocks, respectively, to the left hand thread and to the right hand thread, four pivot pins, one for each block, means slidably mounting each pivot pin in a respective block, each of said two entering rails having a first pin bore and a second pin bore, one of said four pivot pins pivotally connecting a first pin bore to a pin bore in a rail sections, a second of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section, a third of said four pivot pins pivotally connecting a first pin bore in an entering rail to a pin bore in a rail section and a fourth of said four pivot pins pivotally connecting a second pin bore in an entering rail to a pin bore in a rail section, to align said two sprockets, respectively, with said two oppositely disposed endless front rail face track contour paths. 